In one of its aspects, the present invention relates to a retractable needle device. In another of its aspects, the present invention relates to syringe comprising a retractable needle device.
Syringes are generally known.
One class of syringes are manual syringes in which the user actuates pressure on the contents of the syringe thereby dispensing the medicant or other material to be injected to a patient.
Electronic syringes are known in the art. Typical uses for such devices include injecting biocompatible material, specifically anaesthetics such as block, conduction and para-apicalanaesthesia, through bone tissue and administering insulin and other pharmaceuticals.
In most dental applications, practitioners are required to regularly administer anaesthetic injections in confined spaces using conventional manual syringes.
Conventional manual syringes, as used in dentistry applications, usually comprise a hollow cylindrical housing having one end adapted to receive a needle and the other end adapted to receive a piston assembly. The outer surface of the housing is provided with a pair of finger grips such that the device can be held firmly between the middle and index fingers of the practitioner""s hand. Anaesthetic is commonly supplied in premeasured ampules which are designed to fit in to the housing. The ampule has one end provided with a pierceable membrane that receives a proximal end of the needle in sealing engagement and another end fitted with a slidable stopper which engages a distal end of the piston assembly. The piston assembly includes a shaft, which is fitted with a plunger at its distal end and a thumb rest at its proximal end. In operation, the anaesthetic injection is administered by depressing the plunger with the practitioner""s thumb which causes the piston assembly to engage and push the stopper, thereby forcing anaesthetic from the ampule via the needle.
Many of the difficulties associated with manual syringes have been obviated and/or mitigated by the teachings of U.S. Pat. No. 5,690,618 [Smith] and International publication number WO 99/55401 [Smith et al.]. These innovations relate to improving the safety of the syringe device by reducing patient discomfort and fear of the syringes.
Despite these improvements, there is an ongoing need to improve the safety of syringe devices generally.
One of the ongoing safety issues is inadvertent xe2x80x9cstickingxe2x80x9d of the practitioner and/or the patient by an exposed needle. While the needle in conventional syringes typically come with removable caps or sleeves, it would be desirable to have a system in which the needle would automatically extend for injection and retract after injection upon actuation of the plunger normally used to inject the biocompatible material.
It is an object of the present invention to provide a novel retractable needle device which obviates or mitigates at least one of the above-mentioned disadvantages of the prior art.
Accordingly, in one of its aspects, the present invention provides a retractable needle device comprising:
a housing comprising a plunger operable between a first, extended position and a first, retracted position;
a shield portion engaged to the housing, the shield portion comprising a first chamber;
a carpule retraction portion in sliding engagement with plunger,
a carpule releaseably engaged to the carpule retraction portion, the carpule comprising a needle portion, a stopper portion and a second chamber disposed therebetween for receiving an injectable fluid, the carpule being disposed in the first chamber and being movable between a second, extended position in which the needle extends from the shield portion and a second, retracted position in which the needle is contained in the shield portion.
In another of its aspects, the present invention provides a retractable needle device comprising:
a syringe component having an outer housing, a plunger, a plunger driver connected to said plunger and operable to move said plunger between extended and retracted positions, and a secondary carpule housing in sliding communication with said plunger driver;
a safety shield releaseably engageable with said outer housing of said syringe component;
a carpule for containing said biocompatible material, the carpule having a housing with an attached needle, said carpule housing releaseably engageable with said secondary carpule housing of said syringe component, said carpule having an extracted position in which an end portion of said needle extends from said safety shield, and a retracted position in which said needle is contained within said safety shield, when said carpule housing is engaged with said secondary carpule housing and said safety shield is engaged with said outer housing,
wherein when said plunger is moved to the extended position said carpule is moved to the extracted position thereby extending said needle and expelling said biocompatible material, and when said plunger is moved to the retracted position said carpule is moved to the retracted position thereby containing said needle in said safety shield.
In yet another of its aspects, the present invention provides a safety needle device for use with a syringe component, the syringe component having an outer housing, a plunger with a plunger driver connected thereto, said plunger driver operable to move said plunger between extended and retracted positions, and a secondary carpule housing in sliding communication with said plunger driver, said safety needle device having:
a safety shield releaseably engageable with said outer housing of said syringe component;
a carpule for containing said biocompatible material, the carpule having a housing having an attached needle, said carpule housing releaseably engageable with said secondary carpule housing of said syringe component, said carpule having an extracted position in which an end portion of said needle extends from said safety shield, and a retracted position in which said needle is contained within said safety shield, when said carpule housing is engaged with said secondary carpule housing and said safety shield is engaged with said outer housing,
wherein when said plunger is moved to the extended position said carpule is moved to the extracted position thereby extending said needle and expelling said biocompatible material, and when said plunger is moved to the retracted position said carpule is moved to the retracted position thereby containing said needle in said safety shield.
In yet another of its aspects, the present invention provides a retractable needle device for use with a carpule containing a biocompatible material, said device having:
a syringe component having an outer housing, a plunger with a plunger driver connected thereto, said plunger driver operable to move said plunger between extended and retracted positions, and a secondary carpule housing in sliding communication with said plunger driver;
a safety shield releaseably engageable with said outer housing of said syringe component;
a carpule housing having an attached needle, for receiving said carpule, said carpule housing releaseably engageable with said secondary carpule housing of said syringe component, said carpule housing having an extracted position in which an end portion of said needle extends from said safety shield, and a retracted position in which said needle is contained within said safety shield, when said carpule housing is engaged with said secondary carpule housing and said safety shield is engaged with said outer housing,
wherein when said plunger is moved to the extended position said carpule housing is moved to the extracted position thereby extending said needle and expelling said biocompatible material, and when said plunger is moved to the retracted position said carpule housing is moved to the retracted position thereby containing said needle in said safety shield.
In yet another of its aspects, the present invention provides a safety needle device for use with a carpule containing a biocompatible material and a syringe component having an outer housing, a plunger with a plunger driver connected thereto, said plunger driver operable to move said plunger between extended and retracted positions, and a secondary carpule housing in sliding communication with said plunger driver, said safety needle device having:
a safety shield releaseably engageable with said outer housing of said syringe component;
a carpule housing having an attached needle, for receiving said carpule, said carpule housing releaseably engageable with said secondary carpule housing of said syringe component, said carpule housing having an extracted position in which an end portion of said needle extends from said safety shield, and a retracted position in which said needle is contained within said safety shield, when said carpule housing is engaged with said secondary carpule housing and said safety shield is engaged with said outer housing,
wherein when said plunger is moved to the extended position said carpule housing is moved to the extracted position thereby extending said needle and expelling said biocompatible material, and when said plunger is moved to the retracted position said carpule housing is moved to the retracted position thereby containing said needle in said safety shield.
Thus, in one of its aspects, the present invention provides a retractable needle device for use with a syringe. The syringe may be manually driven or electronically driven. In the retracted position, the needle is enclosed within a safety shield and may be extended from the safety shield upon actuation of the plunger normally used to dispense the biocompatible material from the needle. In this instance, initial pressure on the plunger serves to extract the needle and after the needle is extracted, the biocompatible material is dispensed from a carpule in communication with the needle. When it is desired to retract the needle, the direction of the plunger travel is reversed thereby effectively retracting the needle back in to the safety shield.